1. Technical Field
The present invention relates to an electrostatic capacitance input device which is able to detect a position where a finger comes into contact with as a change in electrostatic capacitance, a display apparatus with an input function, and an electronic apparatus.
2. Related Art
In recent years, some of electronic apparatuses such as mobile phone sets, car navigation systems, personal computers, ticket-vending machines, and bank terminals include an input device of a tablet type arranged on a surface of a liquid crystal device or the like thereof, whereby input of data corresponding to instruction images displayed in an image display area of the liquid crystal device is achieved by referring to the instruction images and touching areas where the instruction images are displayed with a finger or the like.
Such the input devices (touch panels) include a resistance film type and an electrostatic capacitance type, and the input device of the resistance film type has a double structure including film and glass and is configured to press the film to short-circuit, so that disadvantages such as the narrowness of the range of the operating temperature or weakness for the change with time are resulted.
In contrast, the electrostatic capacitance input device has an advantage such that a translucent conductive film may simply be formed on a single substrate. In the electrostatic capacitance input device, for example, electrode patterns are extended in the directions intersecting with respect to teach other and an input position is detected by sensing the change of the electrostatic capacitance between electrodes when the finger or the like comes into contact therewith or in proximity thereto (for example, JP-A-2005-337773).
In the electrostatic capacitance input device as described above, for example, as shown in FIG. 9, a plurality of first translucent electrode patterns 11 extending in a direction X and a plurality of second translucent electrode patterns 12 extending in a direction Y, where the direction X and the direction Y are directions intersecting with respect to each other in the direction of the plane of a substrate, are formed in an input area 10a of the substrate, and a first distribution area 955 having a plurality of first lines 911 to 919 extending from the plurality of first translucent electrode patterns 11 to a first signal input/output area 950 so as to be arranged in parallel to each other and a second distribution area (a short distance second distribution area 961 and a long distance second distribution area 962) having a plurality of second lines 921 to 926 and 929 extending from the plurality of second translucent electrode patterns 12 to a second signal input/output area 960 so as to arranged in parallel to each other are formed in a peripheral area 10e outside the input area 10a on the substrate. The configuration shown in FIG. 9 is thought out by the present inventor for comparing with the invention of this application, and hence is not a related art.
Since the change in the electrostatic capacitance in the electrostatic capacitance input device, if the capacitances which are parasitic on the lines are varied from line-to-line, such variations cannot be absorbed by the correction in a detection circuit and hence the sensitivity of detection is disadvantageously and significantly lowered. In the configuration shown in FIG. 9, the capacitances which are parasitic on the lines vary from line-to-line from the reason described below.
As shown in FIG. 9, when the first signal input/output area 950 is arranged on one side of the input area 10a in terms of the direction Y, the first distribution area 955 extends from an end side 10s on one side of the input area 10a in terms of the direction X to the first signal input/output area 950 along the end side 10s. When the input area 10a is divided into a first input area 101a located on the side of the second signal input/output area 960 in terms of the direction Y and a second input area 102a located on the side opposite from the side of the second signal input/output area 960 in terms of the direction Y so as to enable detection of multipoint instruction although the second signal input/output area 960 is arranged on one side of the input area 10a in terms of the direction Y, the plurality of second lines 921 to 926 to be connected to the second translucent electrode patterns 12 in the second input area 102a extend from an end side 10t located on the opposite side of the input area 10a from the second signal input/output area 960 to the second signal input/output area 960 along one end side 10u of the input area 10a in terms of the direction X.
In such a case, since the lengths of the lines are significantly different among the plurality of first lines 911 to 919, the capacitances which are parasitic between the adjacent lines disadvantageously and significantly different among the first lines 911 to 919 from line-to-line. Also, since the lengths of the lines are significantly different among the plurality of second lines 921 to 926 extending from the second input area 102a, the capacitances which are parasitic between the adjacent lines disadvantageously and significantly different among the second lines 921 to 926 from line-to-line.